Hot-air engine



(No Model.) 2 Sheets-Sheet 1. T. MODONOUG'H.

7 HOT AIR ENGINE. No. 278,446. Patented May 29,1888.

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(No Model.) 2 Sheets-Sheet 2.

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HOT AIR. ENGINE.

No. 273,446. Patented Ma ZQ, 1883.

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f UNITED STATES PATENT Erica.

THOMAS,- MGDONOUGH, or.

HOT-AIR MONTOLAIR, NEW JERSEY.

ENGINE.

sP cIrroATIoN forming part of Letters Patent No. 278,446, dated May 29, 1883,

Application flled October 19, 1882. (No-model.)

T all whom it may concern:

Be itknown that I, THOMAS MoDoNoUeH, a citizen of the United States, residing at Mon'tclair, in the county of Essex and State ofv New Jersey, have invented a new and useful Air-Engine, of which the following is a specificatio t My invention relates to improvements in air-- engines in which heated air, by its expansive force, causes the vertical reciprocation of a plunger-piston, and thus, by,suitable cranks and connecting-bars, imparts motion tothe shalt on which the fly-wheel and pulley are mounted; and the objects of my improvements .are,first, to increase the efficiency of the mo torby lessening the numberof moving parts .second, to increase the durability of the ma chine by dispensing with the wear and tear and, third, to attainpthese objects with the maximum simplicity of construction. 'I attain these objects by the means illustrated in the accompanying drawings, in which Figure 1 represents an elevation, partly in section, of my engine, illustrating the parts essential to its successful operation and their relation each to the other. Fig. 2 is a sectional elevation through the center of the cylinder;

and .Fig. 3 is a horizontal section on theline w a of Fig. 2, illustrating more clearly the re lation between the fly-wheel and the crank and connecting-bars.

Similar letters refer to corresponding parts throughout the several views.

A represents the cylinder ofthe engine. It is made of No. 24 sheet-iron, and is mounted on legs M M to raise it over a suitable medium for raising the temperature of the air in the cylinder. The cylinder A has a flange, A

upon which is laid aflexible diaphragm of rubbenor corrugated leather, E, which is confined between it and the corresponding flange, A.

B represents a plungerpiston concentric with but of smaller diameterthan the cylinder. Its surface is surrounded by wire 0, rigidly wound upon it, so as to partake of its motion. The thickness of the layers of wire is equal to the difference in circumference of the cylinder and the piston. A V-shaped recess, B, is out through the center of the piston to permit the oscillation of the connecting-rod F, which is attached at F by any suitable means.

D represents a piston-fitting thecylinder A, which is attached to the center of the diaphragm E, so as to impart to and receive from the latter motion synchronously.

F is a rod connecting the plunger-piston B with the crank G, which imparts said motion simultaneously to the piston D by means of connecting-ha r H and to the shaft I by crankGf.

J represents a fly-wheel mounted on the shaft I, in order to give steadiness of motion andovercome the dead-centers of the crank G. K represents thin ribs radiating from the outer. surface of the cylinder, to conduct superflous heat therefrom. When a water-jacket used for this purpose these ribs are dispensed 1 with. incident to a largenumber of moving parts; i

between the packing of the outer piston and i the cylinder, without great friction and consequent loss of power. When stationary regenerators are used the efticiencyof the motor is (seriously impaired, because, being fixed in position, they are only aii'ected by the air flowing through them, and are not, as in my device, exposed alternately in the heated and cooled ends of the cylinder, and hence do not amplify the difference in the temperature upon which the successful operation of the air-engine depends. To obviate these ditficulties requires an adaptation of old means invnew juxtaposition, such as is illustrated in the accompanying drawings.

It must be understood that in my engine there are two sources of motion-to wit, that of the plunger-piston B, derived from the expansive force of the heated air; and that of the flexible diaphragm E, due to the difference in J w u with, consequent leakage and motion are oh- 2 mate temperature to which its inner and outer sur- ,faces are exposed- Both of these'motions are directly transmitted to the shaft I and the flywheel J-in the former case by connecting-bar 5 F and cranks G G and in the latter case by connecting-bar H and crank G. By reason of the mechanical adjustment of the parts, the dead centers of the crank G are practically obviated; hence the only dead-centers to overcome are those of the crank G, which occur when the long arm of the crank is perpendicu lar to the connecting-bar H. Inasmuch as the plunger-piston B is directly connected to the crank G, inside the cylinder, packing for the outer piston, usually employed, is dispensed viated, and greater velocity attained. As the regenerator-wire U, wound around the pistonplunger B, partakes of its motion and has simultaneously its upper and lower ends in different temperatures, this difference is materially amplified thereby and its effect transmitted to the tly-wheel, which resultant force is far greater than that produced by the stationary regener- 2 5 ator.

there are two causes for the heating of the upper portion of the cylindorto Wit, the conduction of its metal'and the surplus heat of the airthat has performed its function and is 0 not taken up by the balls Ia; In order speedily to remove this heat, 1 make the conduction minimum by employing a cylinder made ofNo. 24 sheet-ironriveted to a castiron or steel hotpot at the bottom, and so finished at its top 5 that the diaphragm maybe secured to it. If

a piston is used, the top end of the sheet-iron is riveted to the bored cylinder in which it slides. To dispose of the remaining heat I employ thin metal ribs K K, set closely around the upper part of the cylinder, to radiate it into space. These ribs are not riveted to, but have metallic contact with, the cylinder throughout their length.

Having/thus fully described my invention, what I claim, and-desire to secure by Letters Patent of the United States, is--- 1. In an air-engine, the combination of a cylinder, A, with a piston, B, concentric with but of less diameter than the cylinder, said piston having layers of wire wound around its entire surface equal in thickness to the difference of the circumferences of the cylinder and piston, substantially as specified.

2. In an air-engine, the combination of the flexible diaphragm E and piston'D, attached thereto, said piston being concentric with and just fitting the inner wall of the cylinder,with

inder, A, having metallic ribs K K radiating therefrom, with the flexible diaphragm'E, pistons B D, connecting-bar's F H, cranks G G, shaft I, fly-wheel J, and metal balls L, substantially as specified.

I THOMAS enououen.

Witnesses:

EDWIN O. FULLER, WM. L. JOHNSON. 

